支持HTML5 SqlLite的AndroidApp

简介：

想要建立一个支持HTML5的Android App;

这个HTML5的程序需要使用本地存储，特别是sqllite;

用eclipse创建了一个app,这个app默认在res/layout建了两个描述界面的xml文件，一个调用另一个，下面的代码基于这种情况;

package com.example.helloweb;



import android.app.Activity;

import android.app.ActionBar;

import android.app.Fragment;

import android.content.Context;

import android.os.Bundle;

import android.view.LayoutInflater;

import android.view.Menu;

import android.view.MenuItem;

import android.view.View;

import android.view.ViewGroup;

import android.os.Build;

import android.webkit.WebChromeClient;

import android.webkit.WebView;

import android.webkit.WebSettings;

import android.webkit.WebStorage.QuotaUpdater;





public class MainActivity extends Activity {



    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);



        // 为了支持HTML5使用数据库(sqlite)的本地存储

        String databasePath = getApplicationContext().getDir("database", Context.MODE_PRIVATE).getPath();

        

        if (savedInstanceState == null) {

            PlaceholderFragment fragment = new PlaceholderFragment();

            fragment.setDatabasePath(databasePath);

            

            getFragmentManager().beginTransaction()

                    .add(R.id.container, fragment)

                    .commit();

        }

    }



    @Override

    public boolean onCreateOptionsMenu(Menu menu) {

        

        // Inflate the menu; this adds items to the action bar if it is present.

        getMenuInflater().inflate(R.menu.main, menu);

        return true;

    }



    @Override

    public boolean onOptionsItemSelected(MenuItem item) {

        // Handle action bar item clicks here. The action bar will

        // automatically handle clicks on the Home/Up button, so long

        // as you specify a parent activity in AndroidManifest.xml.

        int id = item.getItemId();

        if (id == R.id.action_settings) {

            return true;

        }

        return super.onOptionsItemSelected(item);

    }



    /**

     * A placeholder fragment containing a simple view.

     * 被实例化，作为子UI的类

     */

    public static class PlaceholderFragment extends Fragment {

        String databasePath;

        

        public PlaceholderFragment() {    

        }

        

        // 拿到MainActivity生成的数据库路径

        public void setDatabasePath(String databasePath){

            this.databasePath = databasePath;

        }



        @Override

        public View onCreateView(LayoutInflater inflater, ViewGroup container,

                Bundle savedInstanceState) {

            

            View rootView = inflater.inflate(R.layout.fragment_main, container, false);



            // 通过IDE在子UI里拖进去一个webView,所以这里从rootView里查找

            WebView  webView = (WebView)rootView.findViewById(R.id.webView1);

            webView.setWebChromeClient(this.makeWebChromeClient());

            

            WebSettings webSettings = webView.getSettings();       

            webSettings.setJavaScriptEnabled(true);

            webSettings.setDatabaseEnabled(true);

            webSettings.setDatabasePath(this.databasePath);

            

            // 可以加载本地和网络的资源，加载网络资源需要配置权限

            //webView.loadUrl("http://www.csdn.net/");

            webView.loadUrl("file:///android_asset/demo.html");   

            return rootView;

        }

        

        private WebChromeClient makeWebChromeClient(){

            return new WebChromeClient(){

                @Override

                public void onExceededDatabaseQuota(

                    String url,

                    String databaseIdentifier,

                    long currentQuota,

                    long estimatedSize,

                    long totalUsedQuota,

                    QuotaUpdater quotaUpdater) {

                        quotaUpdater.updateQuota(5 * 1024 * 1024);

                    }

            };

        }   

    }

}

 

配置app访问网络的权限（在AndroidManifest.xml文件里配置）

<?xml version="1.0" encoding="utf-8"?>

<manifest>



    <uses-permission android:name="android.permission.INTERNET" /> 

    

    <uses-sdk/>

    <application></application>



</manifest>

 如果要使用HTML5的localStorage还是要设置databasepath和打开localStorage

webSettings.setDatabasePath(this.databasePath);

webSettings.setDomStorageEnabled(true);